You just won the lottery. How do you build the most stable HA server?

My knowledge of python virtual environments is pretty bad. Is it really that simple? This thread: Python 3.6 upgrade of a virtualenv seems to imply there’s a lot more to it. There also seems to be an issue with openzwave, does that mean all my zwave IDs will change? That’s not a huge deal but like I said I’m looking for the most stable environment and am willing to put in a little work now to do things right if it means not having to redo it again in 6 months.